Mitochondria are the powerhouses of the cell, but even though they supply critical energy to keep everything else running, genome researchers often ignore them. Hey, mitochondria have genomes, too! What do they have to do for attention, stage an “Occupy Cell” demonstration? Now that researchers in Australia have discovered long noncoding RNAs (lncRNAs) in human mitochondria, they’re finally getting a little coverage.
The researchers analyzed deep-sequencing data and discovered three brand-new, abundant lncRNAs (lncND5, lncND6, and lncCytb) in human mitochondria. They verified that these lncRNAs exist by Northern blotting and strand-specific qRT-PCR. Here’s what else they discovered:
- The nuclear-encoded proteins ELAC2, MRPP1, MRPP3, PTCD1, and PTCD2 regulate the levels of mitochondria-derived lncRNAs.
- The three lncRNAs are enriched in mitochondria.
- Without MRPP1, the lncRNAs don’t accumulate very much.
- MRPP1 also is important in the processing of the lncRNA ends.
- lncRNAs form duplexes, possibly with their respective mRNA counterparts.
- The levels of lncRNAs vary in different cell types; reproductive tissues have the highest levels.
The scientists say that the evidence suggests that lncRNAs could have a functional role in regulating gene expression in the mitochondria.
Learn more about mitochondrial lncRNAs at RNA, October 2011.